// Copyright (C) 2012 Yury Bychenkov (http://bychenkov.com).
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//  - Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//  - Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//  - Neither the name of Yury Bychenkov nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef queryexecutor_h
#define queryexecutor_h

#include "query.h"
#include "tuple.h"
#include "heap.h"

template <typename Provider>
class QueryExecutor {
public:
	static const uint MAX_FILTERABLE_COLUMNS = 128;

	static QueryExecutor* link(const Query& query, const Provider& provider);

	template <typename Consumer> uint execute(Consumer& consumer, uint8* memory, uint memorySize) const;
	void explain(ostream& os);

	~QueryExecutor();

private:
	struct Pivot {
		uint columnIndex;
		uint type;
		bool useIndex;
		bool asc;
	};

	QueryExecutor(const Query& query, const Provider& provider);

	bool link();
	bool eliminateInvariant(const uint16* p, int indexValue, int indexCardinality);
	void eliminateCodeBlock(uint start, uint size);
	void buildRangeFilter();
	bool matches(typename Provider::Cursor& cursor) const;

	void buildTuple(typename Provider::Cursor& cursor, TupleBuilder& tupleBuilder, uint fromIndex, uint toIndex) const;

private:
	const Query& query;
	const Provider& provider;
	uint16* code;
	uint codeCount;

	Pivot* pivots;
	uint pivotCount;
	uint orderingPivotCount;

	uint* columnMapping;
	uint columnCount;
	
	uint32* rangeFilter;
	uint rangeFilterCount;
};


#include "queryexecutor.hpp"

#endif // queryexecutor_h
